Abstract: A method and apparatus for adjusting an antenna to maximize the strength of a program information signal.

Abstract: A waveguide coupler for coupling electromagnetic power between a first rectangular waveguide and a second rectangular waveguide includes a one-dimensional intermediate waveguide formed of two plates spaced apart by a distance equal to a common height of the two waveguides. This enables a wave emanating from the first waveguide to spread apart transversely so as to equal the width of the second waveguide, the width of the second waveguide being greater than the width of the first waveguide. A cylindrical lens is located between the intermediate waveguide and the second waveguide to provide for a conversion between a cylindrical wavefront and a planar wavefront. The coupler is operative in reciprocal fashion such that a wave emanating from the first waveguide spreads out in width and is then converted to a planar waveguide prior to entering the second waveguide; and a wave emanating from the second waveguide is converted to a wave of contracting width for entry into the first waveguide.

Abstract: A radiation protection system is operative within an optical section of a radiation imaging system for protection of an array of detectors of the radiation. The protection system is formed of one or more spark boards arranged in series along a path of radiation propagation, the spark boards having a central window through which the radiation propagates. On a front side of each spark board are arranged a set of electrodes disposed about a periphery of the window. Ground pads are disposed on a back side of each board in registration with the electrodes on the front side to form therewith a set of capacitors. A capacitive-discharge power-supply circuit is connected to a first pair of electrodes in a first one of said boards. In the presence of excessive incident radiation power, a capacitor of the power supply circuit is switched to apply a high voltage across said first pair of electrodes, the voltage being high enough to initiate an arc across the window in said first board.

Abstract: In an imaging system employing an array of detectors and an optical system for focusing rays of an image upon the detectors, there is provided a protection system in the form of a cell of gaseous lasing material disposed along a path of the imaging rays. A pair of electrodes and a supply of electric power induces an electric discharge through the lasing medium to heat the medium so as to enhance interaction between intense laser radiation which might inadvertently or deliberately, be directed toward the array of detectors. The laser radiation induces still further heating of the lasing medium with a resultant absorption of a relatively narrow frequency band of radiation, at the lasing frequency, so as to prevent damage to the array of detectors while allowing scene radiation outside of the narrow band to be received by the detectors.